#pragma GCC optimize("O2")
#include <algorithm>
#include <array>
#include <bit>
#include <bitset>
#include <cassert>
#include <cctype>
#include <cfenv>
#include <cfloat>
#include <chrono>
#include <cinttypes>
#include <climits>
#include <cmath>
#include <compare>
#include <complex>
#include <concepts>
#include <cstdarg>
#include <cstddef>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <deque>
#include <fstream>
#include <functional>
#include <initializer_list>
#include <iomanip>
#include <ios>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <map>
#include <memory>
#include <new>
#include <numbers>
#include <numeric>
#include <ostream>
#include <queue>
#include <random>
#include <ranges>
#include <set>
#include <span>
#include <sstream>
#include <stack>
#include <streambuf>
#include <string>
#include <tuple>
#include <type_traits>
#include <variant>

#define int ll
#define INT128_MAX (__int128)(((unsigned __int128) 1 << ((sizeof(__int128) * __CHAR_BIT__) - 1)) - 1)
#define INT128_MIN (-INT128_MAX - 1)

#ifdef DEBUG
#define dbg(x) cout << (#x) << " = " << x << '\n'
#else
#define dbg(x)
#endif

namespace R = std::ranges;
namespace V = std::views;

using namespace std;

using ll = long long;
using ull = unsigned long long;
using ldb = long double;
//#define double ldb

template<class T, size_t N>
ostream& operator<<(ostream& os, const array<T, N> &arr) {
  for(const T &X : arr)
    os << X << ' ';
  return os;
}
template<class T>
ostream& operator<<(ostream& os, const vector<T> &vec) {
  for(const T &X : vec)
    os << X << ' ';
  return os;
}
template<class T>
ostream& operator<<(ostream& os, const set<T> &s) {
  for(const T &x : s)
    os << x << ' ';
  return os;
}

/**
 * template name: palindromicTree
 * author: Misuki
 * last update: 2024/01/13
 * verify: yukicoder - No.2606 Mirror Relay
 */

template<unsigned sigma = 26, char base = 'a'>
struct palindromicTree {
  vector<int> len, link;
  vector<ll> freq;
  vector<array<int, sigma>> go;

  palindromicTree(string s) {
    array<int, sigma> unit;
    fill(unit.begin(), unit.end(), -1);
    len = link = {-1, 0}, go = {unit, unit}, freq = {0, 0};
    len.reserve(ssize(s) + 2);
    link.reserve(ssize(s) + 2);
    go.reserve(ssize(s) + 2);
    freq.reserve(ssize(s) + 2);

    int v = 0;
    for(int i = 0; i < ssize(s); i++) {
      while(len[v] == i or s[i - len[v] - 1] != s[i])
        v = link[v];
      if (go[v][s[i] - base] == -1) {
        go[v][s[i] - base] = ssize(len);
        len.emplace_back(len[v] + 2);
        freq.emplace_back();
        go.emplace_back(unit);
        int u = link[v];
        while(u != -1 and s[i - len[u] - 1] != s[i])
          u = link[u];
        link.emplace_back(u == -1 ? 1 : go[u][s[i] - base]);
      }
      v = go[v][s[i] - base];
      freq[v]++;
    }

    for(int i = ssize(len) - 1; i > 0; i--)
      freq[link[i]] += freq[i];
    freq[0] = freq[1] = 0;
  }
};

signed main() {
  ios::sync_with_stdio(false), cin.tie(NULL);

  string s; cin >> s;
  
  palindromicTree pt(s);
  vector<ll> dp(ssize(pt.len));
  for(int i = 2; i < ssize(pt.len); i++)
    dp[i] = dp[pt.link[i]] + pt.freq[i] * pt.len[i];

  cout << R::max(dp) << '\n';

  return 0;
}